Rear frame X member?
- Thread starter Chuck Leeper
- Start date
Thanks Conrad, I have a question for you if you don't mind. Is there a such thing as the frame is too stiff? I was told by someone that my frame is going to be so stiff that I my car is going to ride all crappy. He was telling me that you need some flex in your frame.
TIA
Prasad
Prasad,
I think we are a LONG way from having a "too stiff" chassis. I have not heard that from anyone whose opinion I would respect.
Have you thought about boxing the center part of the frame...currently a "C" section (under the passenger compartment)? I cannot tell if you have already done that or not.
I like the two bars that run longitudionally from front crossmember to rear crossmember along the frame in the middle. FWIW, the one brace on that long tube will only serve to stop it from acting like a long column (bending in the middle). It will not add any strength to frame. I learned in Statics class in college that any brace that is 90 degrees (perpendicular) to another brace adds no strength. Best run that brace at an angle to get some trianglation.
Comparing your photos to my GN...will the last round bar going toward the rear (one w/o "" bracing) interfere with your gas tank? Looks like it would on my GN....but I have an aftermarket (Ricks SS) tank. Have you tried bolting your rear springs and shocks to the chassis? Curious.
Great job! You should be proud of your work!!!
Conrad
I think we are a LONG way from having a "too stiff" chassis. I have not heard that from anyone whose opinion I would respect.
Have you thought about boxing the center part of the frame...currently a "C" section (under the passenger compartment)? I cannot tell if you have already done that or not.
I like the two bars that run longitudionally from front crossmember to rear crossmember along the frame in the middle. FWIW, the one brace on that long tube will only serve to stop it from acting like a long column (bending in the middle). It will not add any strength to frame. I learned in Statics class in college that any brace that is 90 degrees (perpendicular) to another brace adds no strength. Best run that brace at an angle to get some trianglation.
Comparing your photos to my GN...will the last round bar going toward the rear (one w/o "" bracing) interfere with your gas tank? Looks like it would on my GN....but I have an aftermarket (Ricks SS) tank. Have you tried bolting your rear springs and shocks to the chassis? Curious.
Great job! You should be proud of your work!!!
Conrad
Thanks again Conrad, here is front view before it was sand blasted and powder coated. You can see the I boxed everything up also I welded in tabs to the frame for the roll bar to actually bolt on to the frame. I just didn't want to cut up the body and weld it solid to the frame. I am not a racer so don't care about the NHRA rules. I know it might be an over kill but I got carried away..lol. I had the body and the rear end on and off several times. The only issue I saw was; if I remove the spring and shocks and jack the rear end all the way up into the body, the upper control arm will make contact with front tubing that the X is connected but I don't think the rear end will travel up that fan anyway. As far as the gas tank, I mocked it up with Aluminum tank from GN 1 performance with the sump in the back. Now I am having second thought. I may try the stock tank and see if it would clear and just use two Walbro 416 pumps in the tanks with a custom sending unit which should support 1000hp
I would like to add to see if anyone remembers, but years ago there was a post on a guy from the Motnecarlo board I think that made a brace that went from seatbelt D ring to seatbelt D ring and was under the panel and headliner. It was stated it stiffened up thin quite a bit.
If I remember correctly it was flat stock to a short piece if 1" square tube back to flat stock that went up and over to the other side
If I remember correctly it was flat stock to a short piece if 1" square tube back to flat stock that went up and over to the other side
J-B Racing
Forced Induction
- Joined
- Sep 16, 2003
I think the trailer hitch is a great idea. You can also use the receiver to mount a chute.
Posted from the TurboBuick.Com mobile app
Posted from the TurboBuick.Com mobile app
Yes, you can make a frame to stiff. If you use stock bushings ect on the suspension there will be a lot of road noise and vibration transferred to the body, but if you use heim type replacements the the suspension will take a lot of the movement and noise out of the chassis.
Prasad,
Thanks for the full view photo before paint. That helps a lot. I love what you have done. Should be great! If street car, go with poly body bushings. If track only, go with aluminum bushings. Let us all know how your chassis mods work for you. You should be proud of what you have done.
Conrad
Thanks for the full view photo before paint. That helps a lot. I love what you have done. Should be great! If street car, go with poly body bushings. If track only, go with aluminum bushings. Let us all know how your chassis mods work for you. You should be proud of what you have done.
Conrad
usetaboost
SAY CAR RAMROD!!
- Joined
- May 4, 2005
Prasad, I think your frame will be more than adequate. Keith's car just has a welded frame if memory serves correct along with poly body mounts and it's stiff as hell. What's the chances of building a bolt in brace for the rear crossmember to stop it from flexing? The body x-braces are a joke.
dartguy340
T-Type guy
- Joined
- Oct 2, 2010
WIKEDV6: That work on the frame really looks nice!
I used schedule 40 tubing from a metal supply store. I want to say it's a two inch but I have to double check. It's basically the same diameter as the tubing used for roll cages.
HTH
Prasad
Prasad, thank you! If I have the time I may do something like this. I am already boxing the frame. It looks as if you were able to bend the bars close to the stock floor pans and around the trans Xmember. Again, looks great.
Didn't mean to jack the thread either fella's!
If it helps, The key is to get the bar that goes across and over the drive shaft in place first then you can build from there. The body has to be on and off several times I actually made all the bends and pieces with PVC tubing. I used the propane torch to heat up and bend the tubing. I am cheap so I figured it's cheaper to screw up the PVC pipes than the actual metal tubing. The burned plastic smell was unbearable!...
HTH
Prasad
HTH
Prasad
Great tips on the PVC, I would have thought of that AFTER I did it, lol.
Thought I would add what I did to my Monte Carlo frame when I was working on it....I dont claim any of the idea's or design, just some common sense to me and idea's from websites like this and Yellowbullet. The bars that run down and forward tie into the UCA mount, and everything was designed to clear the larger ears of the Moser 12 bolt housing.
A simple test I did to see the difference was a 100% bare frame on 4 jackstands. Stock, I could lift up on either rear frame horn and pick it up about 3-4" before any other part of the frame lifted of its jackstand. After all of that and the boxing it was instantly picking up the other rear with one front. Huge difference.
A simple test I did to see the difference was a 100% bare frame on 4 jackstands. Stock, I could lift up on either rear frame horn and pick it up about 3-4" before any other part of the frame lifted of its jackstand. After all of that and the boxing it was instantly picking up the other rear with one front. Huge difference.
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